Process for making electrodes for lithium based electrochemical cells

A process for making an electrode sheet for a solid lithium electrochemical cell comprising the steps of:

• a) admixing a polyether polymer or copolymer, at least one lithium salt, at least one electrochemically active material and purified water to form an aqueous solution/suspension containing by weight at least 40% purified water, at least 20% electrochemically active material, up to 10% electrically conductive material, at least 5% polyether polymer or copolymer, and at least 1.5% lithium salt;
• b) coating the aqueous solution/suspension in the form of an electrode thin film onto an electrode support;
• and,
• c) evaporating the water from the electrode thin film through a dryer/oven consisting of a tunnel having incremental drying zones including heated gases ranging from 100° C. to 160° C. under a nitrogen gas sweep to obtain an electrode sheet having less than 1000 ppm of residual water and less than 10% porosity.